Common lines and tubes
Nasogastric tubes   >>   Used to feed patients and aspirate stomach contents. Tip lies in the stomach.
Chest drains   >>      Used to drain fluid or air from the pleural cavity.
Endotracheal tubes   >>     Used to ventilate the patient.
Central venous lines   >>    Examples include Subclavian line, PICC line, Internal Jugular line
Tunnelled lines   >>    Central venous catheter for long term venous access

Nasogastric tubes:

 

Description:
Catheters of various sizes (for adults usually from 12f to 18f) which have radiopaque markers along the length of the catheter and a radiopaque tip in order that the position of the tube can be determined on a radiograph. The distal 5cm to 10cm of the tube contains side holes.

 

Use:
Used to feed patients and to aspirate the contents of the stomach.

 

Placement:
Usually passed through the nostril, through the oropharynx and pharynx, down the oesophagus and into the stomach. Some tubes have a guidewire to assist placement. The end of the tube MUST lie in the stomach. At least 10cm of the tube must lie distal to the gastro-oesophageal junction to ensure no side holes remain in the oesophagus. This is to ensure there is no risk of aspiration when fluid is passed down the tube.

 

Position:
The end of the nasogstric tube has to lie within the stomach. The position can be determined by aspiration and checking the pH of the aspirate but the most accurate method to check position is to obtain a chest radiograph. On the radiograph the tip of the tube needs to be seen below the diaphragm and a long portion of the tube must be below the gastro-oesophageal junction. If there is any doubt regarding the position of the tube it should not be used.

 

Complications:
The most common complication is that the tube passes in to the bronchus not the oesophagus. This could have disastrous consequences. If the patient is fed via a nasogastric tube which is in an airway it could lead to death. If the tube lies in the oesophagus and has not entered the stomach there is a signficant risk of aspiration.

 

Further Images: image 1   >>           image 2   >>           image 3   >>           top of page    >>

 

 

Chest Drains:

 

Description:
(= intercostal drain). Various sizes are used (6f to 30f commonly). There are radiopaque markers along the length of the drain so it can be seen on a radiograph. The drain usually has multiple side holes in the distal end.

 

BTS guidelines for chest drain insertion: http://thorax.bmj.com/content/58/suppl_2/ii53.full

 

Use:
To drain fluid or air from the pleural cavity.

 

Placement:
Inserted through the chest wall into the pleural cavity. The catheter is usually passed over a wire using the Seldinger technique. Larger drains are sometimes inserted using a trocar and blunt dissection although some centres no longer use trocars due to the risk of complications. Ultrasound may be used to assist placement of the catheter in the correct position. Any suitable position through the chest wall can be used provided vital structures are not obstructing insertion. Commonly the catheter is placed in a midaxillary position through the 'safe triangle'.

 

Position:
The end of the drain and all its side holes has to be within the pleural cavity. For a pneumothorax it is better for the drain to point towards the apex of the lung. For the drainage of fluid the drain should point towards the lung base. But if adequate drainage is obtained any position in the pleural space is ok.

 

Complications:
Damage to surrounding structures is possible. For example if placed too low the chest drain may damage the spleen or liver. It is important to remember how high the liver and spleen can lie. If there is any doubt about the safety of the procedure then ultrasound may help to demonstrate the position of the diaphragm and vital structures. If all the side holes of the catheter are not within the pleural cavity this can lead to complications. Surgical emphysema (gas in the subcutaneous tissues) may result from incorrect insertion.

 

Further Images: image 1   >>           image 2   >>           image 3   >>           top of page    >>

 

 

Endotracheal Tubes:

 

Description:
Various sizes are used. There is usually radiopaque markers along the length of the tube so it can be seen on a radiograph.

 

Use:
For artifical ventilation.

 

Placement:
A laryngoscope is used to insert an endotracheal tube in to the trachea.

 

Position:
The end of the tube should lie approximately 6cm above the carina (in an adult) or approximately just below the level of the medial ends of the clavicles.

 

Complications:
The tube can be incorrectly placed in the right or left main bronchus (most commonly in the right bronchus). This can lead to collapse of whole or part of the opposite lung. There is the risk of pneumothorax affecting the lung supplied by the bronchus within which the tube lies. It is also possible for it to be incorrectly placed in the oesophagus. This can lead to signficant gastric dilatation.

 

Further Images: image 1   >>           image 2   >>           image 3   >> top of page    >>

Central venous lines:

 

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Tunnelled lines:

 

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